drivers: serial: Add in UART for ADI SC5XX-family processors
Co-developed-by: Greg Malysa <greg.malysa@timesys.com>
Signed-off-by: Greg Malysa <greg.malysa@timesys.com>
Co-developed-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Vasileios Bimpikas <vasileios.bimpikas@analog.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>
Signed-off-by: Arturs Artamonovs <arturs.artamonovs@analog.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 831f6da..1de9cb7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -611,6 +611,7 @@
F: arch/arm/include/asm/arch-adi/
F: arch/arm/mach-sc5xx/
F: drivers/clk/adi/
+F: drivers/serial/serial_adi_uart4.c
F: include/env/adi/
ARM SNAPDRAGON
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 403ab1d..dbe598b 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -65,3 +65,4 @@
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_USB_TTY) += usbtty.o
endif
+obj-$(CONFIG_UART4_SERIAL) += serial_adi_uart4.o
diff --git a/drivers/serial/serial_adi_uart4.c b/drivers/serial/serial_adi_uart4.c
new file mode 100644
index 0000000..45f8315
--- /dev/null
+++ b/drivers/serial/serial_adi_uart4.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (C) Copyright 2022 - Analog Devices, Inc.
+ *
+ * Written and/or maintained by Timesys Corporation
+ *
+ * Converted to driver model by Nathan Barrett-Morrison
+ *
+ * Contact: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
+ * Contact: Greg Malysa <greg.malysa@timesys.com>
+ *
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <serial.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <linux/bitops.h>
+
+/*
+ * UART4 Masks
+ */
+
+/* UART_CONTROL */
+#define UEN BIT(0)
+#define LOOP_ENA BIT(1)
+#define UMOD (3 << 4)
+#define UMOD_UART (0 << 4)
+#define UMOD_MDB BIT(4)
+#define UMOD_IRDA BIT(4)
+#define WLS (3 << 8)
+#define WLS_5 (0 << 8)
+#define WLS_6 BIT(8)
+#define WLS_7 (2 << 8)
+#define WLS_8 (3 << 8)
+#define STB BIT(12)
+#define STBH BIT(13)
+#define PEN BIT(14)
+#define EPS BIT(15)
+#define STP BIT(16)
+#define FPE BIT(17)
+#define FFE BIT(18)
+#define SB BIT(19)
+#define FCPOL BIT(22)
+#define RPOLC BIT(23)
+#define TPOLC BIT(24)
+#define MRTS BIT(25)
+#define XOFF BIT(26)
+#define ARTS BIT(27)
+#define ACTS BIT(28)
+#define RFIT BIT(29)
+#define RFRT BIT(30)
+
+/* UART_STATUS */
+#define DR BIT(0)
+#define OE BIT(1)
+#define PE BIT(2)
+#define FE BIT(3)
+#define BI BIT(4)
+#define THRE BIT(5)
+#define TEMT BIT(7)
+#define TFI BIT(8)
+#define ASTKY BIT(9)
+#define ADDR BIT(10)
+#define RO BIT(11)
+#define SCTS BIT(12)
+#define CTS BIT(16)
+#define RFCS BIT(17)
+
+/* UART_EMASK */
+#define ERBFI BIT(0)
+#define ETBEI BIT(1)
+#define ELSI BIT(2)
+#define EDSSI BIT(3)
+#define EDTPTI BIT(4)
+#define ETFI BIT(5)
+#define ERFCI BIT(6)
+#define EAWI BIT(7)
+#define ERXS BIT(8)
+#define ETXS BIT(9)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct uart4_reg {
+ u32 revid;
+ u32 control;
+ u32 status;
+ u32 scr;
+ u32 clock;
+ u32 emask;
+ u32 emaskst;
+ u32 emaskcl;
+ u32 rbr;
+ u32 thr;
+ u32 taip;
+ u32 tsr;
+ u32 rsr;
+ u32 txdiv_cnt;
+ u32 rxdiv_cnt;
+};
+
+struct adi_uart4_platdata {
+ // Hardware registers
+ struct uart4_reg *regs;
+
+ // Enable divide-by-one baud rate setting
+ bool edbo;
+};
+
+static int adi_uart4_set_brg(struct udevice *dev, int baudrate)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ struct uart4_reg *regs = plat->regs;
+ u32 divisor, uart_base_clk_rate;
+ struct clk uart_base_clk;
+
+ if (clk_get_by_index(dev, 0, &uart_base_clk)) {
+ dev_err(dev, "Could not get UART base clock\n");
+ return -1;
+ }
+
+ uart_base_clk_rate = clk_get_rate(&uart_base_clk);
+
+ if (plat->edbo) {
+ u16 divisor16 = (uart_base_clk_rate + (baudrate / 2)) / baudrate;
+
+ divisor = divisor16 | BIT(31);
+ } else {
+ // Divisor is only 16 bits
+ divisor = 0x0000ffff & ((uart_base_clk_rate + (baudrate * 8)) / (baudrate * 16));
+ }
+
+ writel(divisor, ®s->clock);
+ return 0;
+}
+
+static int adi_uart4_pending(struct udevice *dev, bool input)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ struct uart4_reg *regs = plat->regs;
+
+ if (input)
+ return (readl(®s->status) & DR) ? 1 : 0;
+ else
+ return (readl(®s->status) & THRE) ? 0 : 1;
+}
+
+static int adi_uart4_getc(struct udevice *dev)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ struct uart4_reg *regs = plat->regs;
+ int uart_rbr_val;
+
+ if (!adi_uart4_pending(dev, true))
+ return -EAGAIN;
+
+ uart_rbr_val = readl(®s->rbr);
+ writel(-1, ®s->status);
+
+ return uart_rbr_val;
+}
+
+static int adi_uart4_putc(struct udevice *dev, const char ch)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ struct uart4_reg *regs = plat->regs;
+
+ if (adi_uart4_pending(dev, false))
+ return -EAGAIN;
+
+ writel(ch, ®s->thr);
+ return 0;
+}
+
+static const struct dm_serial_ops adi_uart4_serial_ops = {
+ .setbrg = adi_uart4_set_brg,
+ .getc = adi_uart4_getc,
+ .putc = adi_uart4_putc,
+ .pending = adi_uart4_pending,
+};
+
+static int adi_uart4_of_to_plat(struct udevice *dev)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ fdt_addr_t addr;
+
+ addr = dev_read_addr(dev);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ plat->regs = (struct uart4_reg *)addr;
+ plat->edbo = dev_read_bool(dev, "adi,enable-edbo");
+
+ return 0;
+}
+
+static int adi_uart4_probe(struct udevice *dev)
+{
+ struct adi_uart4_platdata *plat = dev_get_plat(dev);
+ struct uart4_reg *regs = plat->regs;
+
+ /* always enable UART to 8-bit mode */
+ writel(UEN | UMOD_UART | WLS_8, ®s->control);
+
+ writel(-1, ®s->status);
+
+ return 0;
+}
+
+static const struct udevice_id adi_uart4_serial_ids[] = {
+ { .compatible = "adi,uart4" },
+ { }
+};
+
+U_BOOT_DRIVER(serial_adi_uart4) = {
+ .name = "serial_adi_uart4",
+ .id = UCLASS_SERIAL,
+ .of_match = adi_uart4_serial_ids,
+ .of_to_plat = adi_uart4_of_to_plat,
+ .plat_auto = sizeof(struct adi_uart4_platdata),
+ .probe = adi_uart4_probe,
+ .ops = &adi_uart4_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};